1. Field of the Invention:
The present invention concerns the protection of health care workers. More particularly, the present invention concerns means for preventing the inadvertent injury or infection of a health care workers from infected needles, stylets or cannulas in a two-piece needle.
2. Prior Art:
Health care workers today are at great risk of injury or infection with many serious diseases, including AIDS, by contamination from sample-taking instruments. A health care worker can inadvertently injure him/herself with an infected needle. Thus, protection from inadvertent contamination is needed.
Known devices have centered around preventing inadvertent infection in the use of a hypodermic syringe, or a one-piece needle. One such device is set forth in U.S. Pat. No. 4,929,237, issued May 29, 1990 to Medway. Medway teaches a spring-biased needle cover disposed at the front end of the syringe and encompassing the needle. The needle extends beyond the protection cover by a forward thrust. The needle is then withdrawn within the cover. During the injection process, the cover contacts the skin. This contact allows the extension of the needle over the biasing force of the spring. The biasing action of the spring disposed within the cover keeps the cover in place over the needle after the injection. Thus, by the action of the spring, the chance of an inadvertent injection is greatly lessened.
U.S. Pat. No. 4,897,083 issued Jan. 30, 1990 to Martell teaches a telescoping cover disposed around the tubular body of a syringe. The telescoping cover of Martell allows for a shield to be extended around the needle after use. Other similar means are set forth with the following U.S. Patents: U.S. Pat. Nos. 4,985,021; 5,011,479; 4,425,120; 5,024,616; 4,966,592.
Despite these references, their teachings, Applicant knows of no means for protecting users of instruments containing two-piece needles. These are common medical instruments for procedures involving vascular access or fluid/tissue removal. These devices are a source of injury and infection to medical health care workers. The freedom of movement needed to perform biopsies and other procedures unique to two-piece needles necessitate different protective means than those known for single needle instruments. In addition, these prior devices are not applicable to two-piece needles. It is to this need that the present invention is directed.